I'm not sure why this isn't working for you. I've used your input data and your dml (although removed the /r from the final field). Make sure your FbE select expression is exactly as the one below (including the if else logic)

My FbE has the following function
if (next_in_sequence()%2 == 0) 0 else 1

This send records 100, 102, 104, 201, 203 and 205 to the select port and the others to the deselect.

If I change the Fbe to
if (next_in_sequence()%5 == 0) 0 else 1 then I get every fifth record coming out the deselect port and everything else in the select port.

Your statement "Also i want to get every 5 record from my input data (1rec,5rec,10rec,15rec,20rec...)." does not make sense as 1rec is the first record, not the fifth.